#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <limits.h>
#include <sys/types.h>
#include <sys/stat.h>

/* 本程序是消费者程序，它从FIFO读取数据并丢弃他们 */


#define FIFO_NAME "/tmp/my_fifo"
#define BUFFER_SIZE PIPE_BUF

int main()
{
	int pipe_fd;
	int res;
	int open_mode = O_RDONLY;
	char buffer[BUFFER_SIZE + 1];
	int bytes_read = 0;

	memset(buffer, '\0', sizeof(buffer));

	/* 以只读方式打开FIFO文件 */
	printf("Process %d opening FIFO O_RDONLY\n", getpid());
	pipe_fd = open(FIFO_NAME, open_mode);
	printf("Process %d result %d\n", getpid(), pipe_fd);

	if (pipe_fd != -1)
	{
		/* 循环读 */
		do
		{
			res = read(pipe_fd, buffer, BUFFER_SIZE);
			bytes_read += res;
		} while(res > 0);
		(void)close(pipe_fd);
	}
	else
	{
		exit (EXIT_FAILURE);
	}
	printf("Process %d finished, %d bytes read\n", getpid(), bytes_read);
	exit (EXIT_SUCCESS);
}
